RT is not properly syncing with Active Directory

I upgraded RT to 4.4.4.So as a part of that I have removed Ldapimport and added a cronjob.(sbin-rt-ldapimport). It started working but it created another issue.Issue is : I need to add every time the new hires to certain group in active directory to sync them with RT, and by adding them to the group they get the privileged access automatically.
But before upgrade I was adding the new hires independently not to the certain group.Before upgrade I was not adding them to the groups, the people who need the privileged access are being added in the group, but now after I upgrade I am adding them to groups to reflect them in RT, if I add them independently(not to the group) they are not getting reflected in RT.

Kindly let me know how can I fix it, it is a major issue for me.

Please let me know if anyone has got the solution

Can anyone please help?